1. Field of the Invention
This invention relates to a multiple-fold automatic umbrella and particularly to an improved multiple-fold automatic umbrella that has low production cost and high durability.
2. Background of the Invention
Conventional multiple-fold automatic umbrella (such as the four-fold one shown in FIG. 1) basically adapts and expands the structural design of the two-fold or three-fold automatic umbrella. It mainly includes a central shaft means A consisting of four telescopic tubes; a rib assembly B constituting at least: a top rib c pivotally engaged with an upper notch D located at the top end of the central shaft means A, a stretcher rib E pivotally engages with the top rib c and a lower runner F slidably engaged with the central shaft means A, a middle rib G engaged with an outer rib J by means of an outer resilient rib H and an outer connection rib I, the middle rib G further has one end engaging with the stretcher rib E and the top rib c through an inner connection rib K and another end engaging with an inner resilient rib L and the outer connection rib I; an extending spring M located in the central shaft means A for opening the umbrella, a plurality of retracting springs N located in the rib assembly B for closing the umbrella; and a control means P including an upper guide roller Q pivotally located at an upper portion of the central shaft means A, a lower guide roller R pivotally located in the lower runner F and top guide rollers S and X pivotally located at the top end of the central shaft means A for winding a rope T among the rollers to form a multiple-fold automatic umbrella mechanism. The rope T has an inner end fixed on a rod U axially located in the central shaft means A and another end winding through an upper shaft V and the central shaft means and the upper guide roller Q held in an inner block W located at the top portion of the central shaft means, then winding downward around the lower guide roller R and extending upward again to wind around the top guide rollers S and X, and finally winding downward again to engage with the lower runner F. The winding rope T has to change direction several times. The inner block W is small size but has to contain three rollers. The whole assembly becomes bulky. There are many components and is difficult to assemble. The inner connection rib K usually is made by punching a metallic sheet. It is large size and increases cost. The whole design and structure is against the contemporary design concept and trend which focuses small size and light weight.